In the constant technological progress nowadays, the removal of cold or heat is still a big hindrance to the development in the electronic industry. Following the demands for high performance, increased integration and multifunctional applications, the whole electronic industry has to challenge the requirement for good heat dissipation and takes it as a major task to work out a way for upgrading heat transfer efficiency.
A heat sink is usually employed to dissipate heat produced by electronic elements or electronic systems into air. It has been found a heat sink with lower thermal resistance would provide higher heat dissipation efficiency. Generally speaking, thermal resistance consists of spreading resistance existed in the heat sink and convection resistance existed between the surface of the heat sink and the ambient air. In actual application, materials with high thermal conductivity, such as copper and aluminum, are frequently used in the manufacturing of heat sinks with reduced spreading resistance. However, the convection resistance still exists to limit the performance of heat sinks and thereby prevents the new generation of electronic elements from achieving the required heat dissipation efficiency.
Thus, heat dissipation mechanisms capable of providing higher heat dissipation efficiency have drawn consumers' attention in the market. For example, thin heat pipes and vapor chambers with high thermal transfer performance have been used with heat sinks in an attempt to effectively solve the present heat dissipation problem.
The currently available thin heat pipe structure includes a thin pipe body having a hollow space therein. Metal powder is put in the hollow space of the thin pipe body and sintered to form a wick structure on an inner wall surface of the thin pipe body. Alternatively, a metal net structure is arranged in the hollow space of the thin pipe body to serve as a wick structure. Then, the thin pipe body is vacuumed and filled with a working fluid before being sealed to complete a thin heat pipe structure. The conventional thin heat pipe structure does not include any internal supporting structure and is therefore subject to collapse or thermal expansion. When the conventional thin heat pipe structure is subjected to pressure, the wick structure, i.e. the sintered metal powder in the thin pipe body is compressed and damaged to peel off from the inner wall surface of the thin pipe body, which results in largely reduced heat transfer performance of the thin heat pipe structure. Further, with the sintered wick structure formed on the inner wall surface of the thin pipe body or with the metal net structure arranged in the hollow space of the thin pipe body, the working fluid condensed from vapor into liquid flows from the cold end of the heat pipe structure back to the hot end only with the help of gravity or the wick structure on the inner wall surface of the thin pipe body. Thus, the conventional thin heat pipe structure has relatively low vapor-liquid circulation efficiency.
Taiwan New Utility Model Patent Number M336673 discloses a vapor chamber and supporting structure thereof. The vapor chamber includes an enclosure defining a hollow space therein, as well as a wick structure and a supporting structure provided in the enclosure. The supporting structure includes a plate, on which a plurality of symmetrically arranged and spaced channels is provided. In each of the channels, there is formed a corrugated sheet. The corrugated sheets respectively have an upper and a lower end pressed against the wick structure, so that the wick structure is brought to bear on inner wall surfaces of the enclosure. With the corrugated sheets provided in the hollow space of the vapor chamber, the sintered wick structure is prevented from peeling off or collapsing in the vapor chamber and both of the vapor-phase change and the heat transfer speed are increased. However, the corrugated sheets do not provide any significant help in the back flowing of the liquidized working fluid to the hot end or enabling increased capillary limit.
Therefore, the supporting structure in the prior art vapor chamber or thin heat pipe structure still requires improvement. In brief, the prior art chamber and thin heat pipe structure have the following disadvantages: (1) low good yield in production; (2) low vapor-liquid circulation efficiency; and (3) poor internal supporting strength.